| In the highrise building, the anti-lateral force system is the primary factor which the structural design needs to consider. Along with the construction high unceasing enhancement, the lateral force system request also in the unceasing change, the mega-frame system is a new structure system. The mega-frame system is refers in a construction which composed the main structure by several large-scale structural units and the sub-structure which composed with other structural units to work together, thus obtains a bigger stability and the high efficiency highrise building. The mega-frame construction takes one kind of new structure system, not only displays its unique merit in the structure, but also compares other structure systems in the space use to have the superiority. This article uses the ANSYS finite element program analyzed the earthquake resistance and isolation to the mega-frame and the mega-frame -sub-truss-frame. In a word, completed the main work and obtained conclusions are shown as follows:1. Mega-frame construction is different from ordinary frame. This kind of structural style has its own characteristic, but mechanical analysis is complex. This article uses the ANSYS finite element program, has established one mega-frame finite element model, analyzed the earthquake resistance and isolation emulation.2. A new mega-frame-sub-truss-frame system: Add the steel brace between the mega-frame-sub-frame two columns, by substitutes for the shear force wall. This kind of new structure system has the frame construction arrangement agility, and has the big anti-lateral rigidity. This article uses the ANSYS finite element program, has established this mega-frame -sub-truss-frame finite element computation model, analyzed the earthquake resistance and isolation emulation, by judges its feasibility.3. Mega-frame-sub-truss-frame is compare with the mega-frame structure, add the steel brace in the main-frame 3rd, 4 levels frames between the two columns , the structure's vibration periods obviously reduce, specially reduces the bigger influence first 3 steps vibration periods achieve 80%, 60% and 50%. Mega-frame-sub-truss-isolate-frame's vibration periods are relative to mega- isolate-frame separately fall 34%, 16% and 6%; they are relative to mega-frame-sub-truss-frame separately fall 25%, 11% and 6%. And explained the sub-frame establishment braces and the folding rubber base, remarkably increased the sub-structure anti-horizontal displacement rigidity.4. After transferring mega-frame Jo mega-frame-sub-truss-frame, under inputting different earthquake wave, the main-frame displacement responds retain original state. Because increased the sub-frame rigidity, the sub-frame displacement responds obviously reduces, reduces the range to be possible to reach 20% most greatly, explained in the sub-frameincreases the brace, to have the help to limit the sub-structure the horizontal displacement. It not only has satisfied the structure earthquake resistance request, meanwhile cannot because sub-frame rigidity oversized, the earthquake responds for the main-frame creates affects greatly.5. The mega-frame and mega-frame-sub-truss-frame internal force also differs from the input different earthquake wave. Whether the shear force or the bending moment, establishes the brace in the sub-structure, the sub-structure internal force earthquake responds has the reduction, the sub-structural biggest shear force value felled approximately 50%, the bending moment value felled approximately 30%. This result has the very big practical significance in the structural unit section size choice. In this way the sub-structure section size may reduce, increases construction effective useable area, meanwhile reduces the construction cost, obtains the good economic efficiency. Thus it can be seen, mega-frame-sub-truss-frame construction has the good earthquake resistance performance, increases the structure security, at the same time cannot give the main-frame bring the tremendous influence. It is one kind of earthquake resistance performance good structure system.6. Mega-isolate-frame construction has good seismic isolate performance. From the data we can know, in the structure displacement earthquake responds , the culmination displacement in the sub-frame and main-frame are relative to mega-frame, main-frame displacement reduced approximately 58%, the sub-frame displacement reduced approximately 72%; Compares with mega-frame-sub-truss-frame, the main-frame displacement reduced approximately 42%, the sub-frame displacement reduced approximately 65%; In the structure earthquake internal force response, mega-isolate-frame main-frame internal force maximum value earthquake response also felled compared with mega-frame , may fall most greatly to the mega-frame main-structure shear force value 52%, the biggest bending moment value 76%, played to the resistance earthquake role. Therefore, through the establishment seismic isolation, reduced the structure earthquake response, validated seismic isolation system superiority is advantage.7. Mega-frarne-sub-truss-isolate-frame has the seismic isolation performance and brace frame construction merit at the same time. From the data we can know , in the structure displacement earthquake responds, the culmination displacement of the sub-frame and main-frame in mega-frame-sub-truss-isolate-frame are relative to mega- isolate-frame , main-frame displacement reduced approximately 34%, sub-frame displacement reduced approximately 33%; and main-frame displacement reduced approximately 72%, sub-frame displacement reduced approximately 76% compared with mega-frame-sub-truss-frame. In the structure earthquake internal force response, the main-frame of mega-frame-sub-truss -isolate-frame the main frame internal force maximum value earthquake response not only to be lower than the mega-frame-sub-truss-frame (shear force to reduce nearly 33%, bendingmoment reduces nearly 34%), but also be lower than the mega-isolate-frame (shear force to reduce nearly 45%, bending moment reduces nearly 44%). Reduced from the structure displacement and the internal force maximum value response, explained the mega-frame-sub-truss-frame is one kind of earthquake resistance performance good structure system. It has used seismic isolation method improved the structure stress characteristic.8. Under 4 different earthquake waves functions, whether the displacement responds or the internal force response, the conclusions are consistent that the El-centro earthquake wave responds influences the structure obviously.9. After uses the brace truss to replace the entity shear force wall, the mega-frame transforms into the mega-frame-sub-truss-frame may reduce the construction cost, and also reduced the structure self-weight, this is one kind of easy and reasonable effective method. Thus has provided a new idea for the mega-structure earthquake resistance design. |
PDF Full Text Request